Add accessor for SIGTRAP cause in wait status
Add accessor for SIGTRAP cause in wait status

R=rsc
APPROVED=rsc
DELTA=7  (7 added, 0 deleted, 0 changed)
OCL=31563
CL=31565

tav/go,tav/go,tav/go,tav/go,tav/go,tav/go,tav/go